The MTD error: VAT number/user ID mismatch (agents)    
This page is for agents submitting VAT returns for clients using an agent services account. If you are a business submitting returns for your own business, please refer to guidance here.


You have been directed to this page because the VAT number set up in VT is not associated with the government gateway user ID entered when you granted authority.

HMRC error code
HMRC's code for this error is CLIENT_OR_AGENT_NOT_AUTHORISED.

Check your client is linked and signed up
Please see Preparing for MTD for VAT (agents).

Why this error arises
When any MTD application such as VT sends a request to HMRC for a list of your client's VAT returns (or attempts to submit a VAT return), it has to supply two pieces of identifying information. These are the VAT number set up in the application for the client and a 32 character code stored in the application. The code is in turn is derived from the authorisation code issued when you granted authority.

HMRC uses the 32 character code to access the record for the government gateway user ID entered when you granted authority.

This error arises when the VAT number is not one of the ones listed on the record.

Causes and resolution
It follows from the above that the error must be caused by one or more of the following:

1. The client has not been linked to the agent services account
If necessary, please link them now

2. The client is not signed up for MTD or the process is not complete
The process can take up to 72 hours.

It is not uncommon for users to think the client is signed up when they are not.

If the client is signed up, HMRC will have sent a confirmation email. Furthermore if they are signed up they will have an MTD section on their business taxes page on HMRC's web site.

If the client is not signed up for MTD, please sign them up now

3. The client's VAT number set up in VT is incorrect
It is a simple matter to check every single digit. It should be 9 digits long.

4. The wrong government gateway user ID was used when granting authority
VT has no way of knowing what user ID was used to grant authority or of accessing the name of the agent or the type of account. Hence the best thing to do is to simply grant authority again and be very careful that the correct user ID is entered into HMRC's web page.

Please note that an agent should use the government gateway user ID issued for the agent services account and not for any other HMRC online service.

When re-granting authority, also ensure the checkbox labelled I'm using my Agent Services Account... is ticked.

5. There is a fault with the agent services account. This is possible but unlikely. Please contact the HMRC online services helpdesk.

VT would like to assure you that this error does not arise from a software fault in VT.

VT is not able to provide support on the use of HMRC's web site. If necessary, please contact the HMRC online services helpdesk.
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